US5297A - Bridge - Google Patents

Description

UNiTED vsrAriis i?"Airiilnr QFFICEQY SAMUEL F. GASSAWAY, OF MARIETTA, GEORGIA.

BRIDGE,

Specification of Letters Patent No.

To all whom t may concern:

Be it known that I, SAMUEL F. GAssAwAY, of the town of Marietta, in the county of Cobb and State of Georgia, have invented certain new and useful Improvements in the Construction of Suspension Bridges for Supporting Railroads and for other Uses, called Gassaways Improved Suspension- Bridge, which improvements are described as follows, reference being had .to the annexed drawings of the same, making part of this specification.

The nature of my invention and improvement, consists in combining a number of parallel wrought iron suspension chains and horizontal iron chords, with light timber frames, arranged'between them, said chains and chords being secured to horizontal parallel transverse iron bars resting upon stone abutments and piers for supporting the usual parallel strings, crosst ies, and iron rails of a railway-forming at once, a light, strong, durable and cheap structure, adapted to plans where bridges of great span, strength and economy are required.

Figure 1 is a side elevation of the bridge. Fig. 2 is a plan of same.

Each of the parallel suspension chains A,l is composed of a number of wrought iron links coupled together by screw rodsA, and nuts for the purpose of adjusting the tension of the several parallel chains, so that each shall be made to perform its duty; and for lifting and adjusting the light timber frame work B, placed thereon whenever l out of order from any cause. The ends of the chains are well secured to horizontal sta, tionary tranverse bars C, of iron, the outside chains being well fastened to the ends of said bars. One of these bars of iron is laid horizontally and transversely upon the top of each pier, and each abutment between iron posts D, built into the'masonry to secure them from moving longitudinally or transversely. The transverse bars that are secured to the abutments, must be still farther secured to the abutments, by strong iron anchors E, fastened to them and the iron frames, built into the masonry' of the abutments F, or otherwise secured in a permanent manner, so as to counteract the strain upon said bars: all the outside chains are made and secured in the same manner. The transverse bars C, that are placed upon the piers G will require no anchors, as the chains 5,297, dated September 18, 1847.

one side of the pier will counteract the strain on'the opposite side. The intermediate parallel suspension chains, are passed through openings inthe bars and isecured inV a pei'- manent manner by riveting or otherwise.

The number of intermediate piers for sustaining the transverse bars, to depend upon the width of the river to-be bridged, and the extent o-f each span. a

A horizontal wrought iron bridge is formed above the aforesaid suspension chains for supporting the rail-road tracks, or flooring, or whatever is to be constructed or placed thereon, by taking a number of wrought iron rods H, having each a head on` Aone end, and av screw on the other end, and

are placed upon this horizontal wrought iron bridge, and well secured thereto. Likewise a floorl for pedestrians, and a suitable light railing for protection. The permanent and contingent weight brought upon this bridge, produces a longitudinal strain lengthwise of v the grain of the iron of which the parallel suspension rods are composed, from the abutments and piers toward the intermediate cross bars, placed between them and toward the center of the bridge, in proportion to the weight broughtthereon. The vertical descent of the horizontal bridge being resisted by a light frame work M, of diagonal and oblique, and other braces formed andy arranged between the 'suspension chains, and v the horizontal bridge, which impart stiffness f to t-he whole structure: and not only prevents the horizontal track from dropping below its true level, but prevents it from becoming deranged by tempest and other causes. Each of these frames forms a figure corresponding with that formed by the combination of the horizontal rods H, and swinging or suspen-l sion chains A, with the transverse bars C, and approximating to the form of a triangular roof-the bars of the triangular frame being. inverted, and brought against the underside of the wrought iron rods or bridge 110` i H, aforesaid, the sloped or inclined sides resting 'on the aforesaid suspension chains A, havingV the ends or acute angles bearing against the piers and abutments.

The bridge may be braced by `horizontal diagonal braces, let into the piers and abutments, if the position. and nature ofthe bridge should require it.

In regard to the size and materialof the abutments and triangular frames, and the length of spans and WidthV of roadway numbers and diameter of the rods, braces, chains and screws, nuts, bars, plates, anchors land other parts of Which the bridge is to be composed, I have not deemed it necessary to vby 4the combination of the rods H, H and A, A With the cross timbers I and the bolsters or transverse plates C resting on the piers as herein set forth.

SAMUEL F. GrASSAWAY.` Witnesses:

I. A. W. JOHNSON, W. H. HUNT.

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